Be intellectually charitable.

Viewpoint diversity is not incompatible with moral or intellectual rigor — in fact it enhances moral and intellectual agility. However, one should always try to engage with the strongest form of a position one disagrees with (that is, “steel-manning” opponents rather than “straw-manning” them). You should be able to describe your interlocutor’s position in a manner that they would, themselves, agree with (see: “Ideological Turing Test”). Try to acknowledge, when possible, the ways in which the actor or idea you are criticizing may be right — be it in part or in full. Look for reasons why the beliefs others hold may be compelling, and assume that others are roughly as reasonable, informed, and intelligent as you.